In order to achieve a state in which devices and systems can only be used by certain, so-called, authorized users, it is known to monitor the authorization of users by the use of coded data. For this purpose, identification systems are employed which prior to an operation of an associated device and system, the user must be prepared to have this coded data reviewed to determine whether the user is authorized to use the device and system. If, the case, the identification system transmits to the device and system data which permits their operation or use or controls the device and system accordingly.
In order to provide coded data for the user in an identification system of this type, it is known to employ a portable storage medium (for example a smart card, a chip card, . . . ) which can be connected by the user with the identification system through suitable interfaces. Furthermore, there are also such wireless communicating data transmitters (radio transmitters) which can exchange data with the identification system over a data transmission path. In addition, identification systems are used in which the user himself or herself can input data intrinsic to the user, for example in the form of codes, identifying names, PIN numbers, TAN numbers and the like.
A drawback of these arrangements is that the devices and systems which are to be monitored can be used independently of whether the user is authorized or conditions are present which would militate against such use, after a user transmits coded data which gives an authorization and the device or systems in reply have been freed for such use.
Thus such arrangements are not suitable to so control the use of devices and machines, like for example hand-held devices, machine tools, portable electrical tools, household devices and the like that their operation is only permitted to authorize users and can thereafter be monitored for that purpose.
It is common that the operation will be interrupted and taken up again at a later point in time. This has in the use of known identification systems the consequence that once an operation has been permitted, the operations can then be continued or take up by nonauthorized users or in an impermissible manner.
Even with a control for the later operation, for example after a predetermined time period or after a new monitoring of the authorization of a user is possible but is in solution for various reasons, for example it is impractical to introduce a user code or authorization data from a storage medium each time the operation is to be recommenced after a hiatus.
In addition, inappropriate operations cannot be prevented in this manner when for example required safety steps have not been taken for the operation of the device or machine. Even an operation by an nonauthorized user, for example a child or a worker who may not be correspondingly skilled, cannot be prevented as long as operation has been permitted, for example during the indicated duration within which a use or operations is permitted without renewed monitoring of a user authorization.